Van Persie joined United from Arsenal in the summer and has started his life at Old Trafford brightly, netting 11 goals in his first 14 games.

The Netherlands international started the Red Devils' midweek clash with Braga on the bench, but made a significant impact after coming on as a substitute, raising questions over United's ability to play without him in the line-up.

Ferguson's men have so far won every game in which the 29-year-old has scored en route to the top of the Premier League table and beyond the Champions League group stage.

"I don't think it's a problem relying on Robin," he said. "Last year, we lost (the title) on goal difference. I don't expect us to lose on goal difference again."

Van Persie has been likened to his compatriot Ruud van Nistelrooy since making the move to United, but Ferguson dismissed the comparison.

"Robin is a very different player to Van Nistelrooy," said Ferguson. "Ruud was a penalty box player. Robin has a different understanding of the game.

"I never thought we'd get him. There was always the feeling that Arsenal would find a way to get him to stay. But once he made his mind to leave we firmed up our interest because he is one of the best in the business."

This Saturday, United will face Aston Villa, a club which Ferguson has enjoyed great success against in recent years. The Scot expressed his concern for his compatriot and Villa counterpart Paul Lambert on the eve of the clash.

"It is a daunting task as Villa are not where everyone expects them to be," Ferguson said. "Paul Lambert has done well as a manager and is still young.

"But it does take time to change teams and you wonder if the managers changing has a big effect on the playing standards of the team because they have had quite a collection over the years."

Meanwhile, Ferguson confirmed he expects captain Nemanja Vidic to be back for the packed festive programme.

"I think it's Christmas time for Vidic," Ferguson said. "If we get him back for Christmas, then I'll be happy. There's been no setback but we cannot take any chances after his cruciate."